How discount + tax is calculated

In the US (and most jurisdictions), sales tax is applied after the discount — you pay tax on the sale price, not the original price. The three steps are:

Sale Price = Original × (1 − Discount/100)

Tax Amount = Sale Price × (Tax Rate / 100)

Total = Sale Price + Tax Amount

Example: $100 item, 20% off, 8% tax → Sale = $80; Tax = $80 × 0.08 = $6.40; Total = $86.40. You save $13.60 compared to buying at full price with tax ($108).

Frequently asked questions

Is sales tax applied before or after the discount?

After the discount, in the US. Tax is calculated on the discounted (sale) price. A $100 item, 20% off, 10% tax: sale price = $80, tax = $8, total = $88. If tax were applied first it would be $110 − $22 = $88 — same result in this case, but that's a coincidence; for non-round numbers the order matters.

Does the state tax rate include local taxes?

The rates in the state selector are the base state rates only. Many cities and counties add their own surcharge on top — for example, California's state rate is 7.25% but most cities add 1–3% more. Check your local rate for the most accurate total, then type it directly into the tax rate field.

Which US states have no sales tax?

Five states charge no state-level sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon. Select "No sales tax (0%)" in the state dropdown if you're shopping in one of these states.

How does this calculator work?

Enter the original price, discount percentage, and your local tax rate (or pick a US state to auto-fill the state base rate). The calculator applies the discount first, then adds tax to the reduced price, and shows the sale price, tax amount, total, and your savings — all updating instantly as you type. Use Share to copy a link with your exact inputs pre-filled.